In vivo nuclear magnetic and electron spin resonance spectroscopy is concerned, inter alia, with the noninvasive observation of metabolic changes in living systems, including animals and humans. Typically, the physiologi- cal (or pathological) state of an organ or tissue is monitored. This multi- faceted approach was developed during the 1980s. It is still a research technique, but will undoubtedly become a clinical tool. We are proud to present this...